fix core: fixes deadlock detector configuration issues

* Adds deadlock\_detector parameter definition to the static schema.
* Replaces `on` and `off` with `enable` and `disable` to prevent implicit conversions to bool during configuration merges.
* Fixes incorrect parsing of enable option.
commit_hash:a3d39e3a11daab8d2543c09e16980edb9e8760d7

Author: lexeyo

core/include/userver/components/manager_controller_component.hpp

@@ -37,7 +37,7 @@ class Manager;
 /// coro_pool.stack_size | size of a single coroutine stack @ref scripts/docs/en/userver/stack.md | 256 * 1024
 /// coro_pool.local_cache_size | local coroutine cache size per thread | 32
 /// coro_pool.stack_usage_monitor_enabled | whether stack usage is accounted and warnings about too high stack usage are logged @ref scripts/docs/en/userver/stack.md | true
-/// coro_pool.deadlock_detector | Coroutines deadlock detector mode. Can slow down the service. One of: off, on, detect-only. | off
+/// coro_pool.deadlock_detector | Coroutines deadlock detection mode. `disabled` disables deadlock detection. `enabled` allows deadlock detection alongs with stacktraces collection. `detect-only` allows only deadlock detection. Deadlock detection could slow down the service. | disabled
 /// event_thread_pool.threads | number of threads to process low level IO system calls (number of ev loops to start in libev) | 2
 /// event_thread_pool.thread_name | set OS thread name to this value | 'event-worker'
 /// components | dictionary of "component name": "options" | -

core/src/components/manager_config.cpp

@@ -115,6 +115,19 @@ additionalProperties: false
                 type: boolean
                 description: stack usage monitor status
                 defaultDescription: true
+            deadlock_detector:
+                type: string
+                description: |
+                    Coroutines deadlock detection mode.
+                        `disabled` disables deadlock detection.
+                        `enabled` allows deadlock detection alongs with stacktraces collection.
+                        `detect-only` allows only deadlock detection.
+                    Deadlock detection could slow down the service.
+                defaultDescription: disabled
+                enum:
+                  - disabled
+                  - enabled
+                  - detect-only
     event_thread_pool:
         type: object
         description: event thread pool options

core/src/engine/deadlock_detector_config.cpp

@@ -6,11 +6,11 @@ namespace engine {
 
 DeadlockDetector Parse(const yaml_config::YamlConfig& value, formats::parse::To<DeadlockDetector>) {
     auto str = value.As<std::string>();
-    if (str == "off") {
+    if (str == "disabled") {
         return DeadlockDetector::kOff;
     }
-    if (str == "on") {
-        return DeadlockDetector::kOff;
+    if (str == "enabled") {
+        return DeadlockDetector::kOn;
     }
     if (str == "detect-only") {
         return DeadlockDetector::kDetectOnly;